Take a shallow pan, and pour in a gallon of liquid starch. You can then
"drop" drops of acrylic paint (watered down so it "drops") onto the
starch, take a feather or comb, and comb it, or swirl it, and then lay
the object to be marbleized on top of that and "pull" it off. The colors
can be removed from the top of the starch with a paper towel, or
newspaper, the same way you would "clean" in the other methods you have
seen or used.
The starch can be reused.
I like using starch because I can use my acrylic paints and don't have
to use oil paints.
We have not only marbleized paper, but plaster sculptures as well using
the starch method.